1. Field
The present disclosure relates to a substrate processing apparatus for processing a substrate such as a semiconductor wafer.
2. Description of the Related Art
A substrate processing apparatus includes therein a substrate container shelf (a shelf) on which a substrate container such as a front opening unified pod (FOUP) is placed. The substrate container is transferred within the substrate processing apparatus by a transfer robot. The transfer robot includes an arm. The transfer robot moves the arm horizontally and then moves the arm downward to place a substrate container which is picked up by the arm on the substrate container shelf. Furthermore, the transfer robot lifts the substrate container from the substrate container shelf by moving the arm horizontally and then moving the arm upward from the bottom of the substrate container shelf.
As described above, in the substrate processing apparatus, when the substrate container is placed on or lifted from the substrate container shelf, a space in which the arm is positioned and a space for moving the arm upward or downward needs to be provided at the bottom of the substrate container shelf. Patent Document 1 discloses a substrate processing apparatus including multi-tier substrate container shelves, in which the multi-tier substrate container shelves are moved upward or downward to secure these spaces.
In order to increase the number of substrate container shelves to be accommodated in a limited space of the substrate processing apparatus (or the number of substrate containers to be accommodated in the substrate processing apparatus), a space needed to transfer and receive the substrate containers should be decreased.